Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Open Access Guideline
Open Access Guideline
Postgraduate Thesis Guideline
Postgraduate Thesis Guideline
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
Three dimensional fracture analysis of orthotropic materials
Download
index.pdf
Date
2012
Author
Akgül, Görkem
Metadata
Show full item record
Item Usage Stats
219
views
223
downloads
Cite This
The main objective of this study is to examine the three-dimensional surface crack problems in orthotropic materials subjected to mechanical or thermal loading. The cracks are modeled and embedded in the orthotropic material by considering semielliptical crack front geometry. In the model special elements are embedded in the crack front region, in this way it is possible to include crack tip singular fields along the crack front. Three-dimensional finite element analyses are conducted to obtain mode I stress intensity factors. The stress intensity factor is calculated by using the displacement correlation technique. In the analysis, collapsed 20-node iso-parametric elements are utilized to simulate strain singularity around the semi-elliptical crack front. The surface crack problem is analyzed under both mechanical and thermal stresses. In the case of mechanical loading, uniform tension and fixed grip tension loading cases are applied on the model. In thermal analysis, thermal boundary conditions are defined. Comparisons of the results generated to those available in the literature verify the developed techniques.
Subject Keywords
Fracture mechanics.
,
Orthothropic materials
,
Thermal stresses.
,
Materials
URI
http://etd.lib.metu.edu.tr/upload/12614334/index.pdf
https://hdl.handle.net/11511/21565
Collections
Graduate School of Natural and Applied Sciences, Thesis
Suggestions
OpenMETU
Core
Three dimensional fracture analysis of FGM coatings under thermomechanical loading
Yildirim, B; Dağ, Serkan; Erdogan, E (Springer Science and Business Media LLC, 2005-04-01)
The main objective of this study is to examine the three dimensional surface crack problems in functionally graded coatings subjected to mode I mechanical or transient thermal loading. The surface cracks are assumed to have a semi-elliptical crack front profile of arbitrary aspect ratio. The cracks are embedded in the functionally graded material (FGM) coating which is perfectly bonded to a homogeneous substrate. A three dimensional finite element method is used to solve the thermal and structural problems....
Oblique surface cracking and crack closure in an orthotropic medium under contact loading
Toktaş, Selim Ercihan; Dağ, Serkan; Department of Mechanical Engineering (2018)
In this study, inclined surface cracks in an elastic orthotropic half-plane exposed to contact loading at the material surface are examined for both open and closed crack assumptions. At first, mixed mode stress intensity factors are computed for fully open crack assumption depending on the solution of singular integral equations, obtained by Full Fourier Transform techniques. Unless fully open crack assumption is valid, the suitable crack closure mode is determined. Both crack tip and full length closure m...
Three dimensional fracture analysis of FGM coatings
Inan, O; Dağ, Serkan; Erdogan, F (2005-01-01)
In this study the three - dimensional surface cracking of a graded coating bonded to a homogeneous substrate is considered. The main objective is to model the subcritical crack growth process in the coated medium under a cyclic mechanical or thermal loading. Because of symmetry, along the crack front conditions of mode I fracture and plane strain deformations are assumed to be satisfied. Thus, at a given location on the crack front the crack propagation rate would be a function of the mode I stress intensit...
Circumferential crack problem for an fgm cylinder under thermal stresses
Dağ, Serkan; Kadıoğlu, Fevzi Suat (1999-01-01)
The main objective of this study is to determine the stress intensity factors associated with a circumferential crack in a thin-walled cylinder subjected to quasi-static thermal loading. The cylinder is assumed to be a functionally graded material In order to make the problem analytically tractable, the thin-walled cylinder is modeled as a layer on an elastic foundation whose thermal and mechanical properties are exponential functions of the thickness coordinate. Hence a plane strain crack problem is obtain...
Microstructural investigation of SAE 1040 steel specimens by ultrasonic measurements
Gür, Cemil Hakan (British Institute of Non-Destructive Testing (BINDT), 2005-07-01)
The aim of this study is to characterise the microstructures of the as-quenched and tempered SAE 1040 steel specimens by sound velocity and attenuation measurements. An initial heat treatment was applied to the specimens to obtain a uniform starting microstructure. Following 850 degrees C/0.5 h austenitisation and water-quenching of all specimens, a tempering process was applied at 200 degrees C and 600 degrees C for 2 h. Microstructures of the specimens were characterised first by metallography and hardnes...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
G. Akgül, “Three dimensional fracture analysis of orthotropic materials,” M.S. - Master of Science, Middle East Technical University, 2012.
